Pilot valve for combined temperature and pressure control apparatus



Sept. 14, 1948.

J. L. KIMBALL ETAL PILOT VALVE FOR COMBINED TEMPERATURE AND PRESSURE CONTROL APPARATUS Filed Nov. 1, 1944 Patented Sept. i4, i948 PILOT VALVE FOR COMBINED TEMPERA- TURE AND PRESSURE CONTROL .APPA- RATUS James L. Kimball and Roy C. Earley, Danvers,

Mass., assllnors Co., Salem, Masa.

to Bunles-Klingemann Mig.

Application November 1, `1944, serial No. 561,444

This invention relates to temperature limiting device for reducing `pressure regulators. More specifically it comprises a pilot valve thermostatically operated adapted to direct the admission of either the high or reduced pressure to the `1 claim. (ci. 251-46) diaphragm chamber of the reducing pressure Y regulator in accordance with predetermined temperature conditions.

The principal object of the invention is in providing a simple pilot attachment `for reducing pressure regulators which will be effective in pre-i venting over heating in hot water systems. A further object is to provide a pilot valve/ having a valve stem so arranged as to be balanced to variations in the high pressure. Another vobject is in ,providing a vent passage from the lower end oi the stuffing box to the low pressure conduit connection. A still further object of the invention is 'to provide a pilot valve having an operating spindle or stem of a uniform diameter'throughout rather than that of the conventional piston valve type which wears shoulders and. is otherwise unsatisfactory. The advantage in using low pressure steam for heating purposes is well understood by heating engineers and for this reason my invention includes a reducing pressure regulator'. such regulators, however, have no control over the rise in temperature when the temperature conditions are such as to require less steam. It is for this reason that a novel thermostatic control as set forth in the following specifications answers a very useful purpose in preventing over heating,

Referring to the drawing Fig. 1 represents a conventional type of reducing pressure regulator. Fig. 2 represents a thermostatically operated pilot valve embodied in our invention. Fig. 3 illustrates the combination as applied to a hot water heating system. 4

Referring to Fig. 1, a valve casing has inlet 2 and outlet 3. A valve 4 is adapted to control the passage of steam from the inlet to the outlet, a diaphragm 5 operates'valve 4 from variations in pressure in a pressure chamber i, a weighted lever l is adapted to normally hold valve 4 in an open position.

Referring now to Fig. 2 a pilot casing has -a high pressure conduit connection 8 and a low pressure conduit connection 9 also a conduit i0 l connecting the pilot valve casing with pressure chamber 6 of the reducing pressure valve. .Within the pilot valve casing is a valve stem il having at its lower end a central passage I2 and cross ports il. This valve stem is operatively connect- 2 ed to a thermostatic bellows i4 which is controlled by a thermotatic bulb IB.

In the operation of this valve conduit 9 is normally in free communication with the pressurechamber 8, and valve 4 of Fig. 1 is governed by the reduced pressure at the outlet 3 of valve casing I, which is the reduced pressure supply to heater i6, see Fig. 3.

Water flows through the heater from inlet i1 to outlet i8 and whenever the water in the heater reaches a predetermined rise in temperature cor- `responding to the adjustment of spring I9 the reduced pressure connection 9 to pressure chamber 8 will be closed by the lowering of stem I i and on a further rise in temperature the high pressure connection 8 will register with ports i3 and central passage i2 thus admitting high pressure steam from the inlet connection 2 of valve casing i directly into pressure chamber G and thereby ,closing valve. 4 in casing I against a further rise in temperature in heater iB. Ona reverse in 'nection to diaphragm chamber 6. We now have effective positions `above and below the neutral position, one effective in the control of temperature and the other in the'controi of pressure.

In a preferred embodiment u! `this invention a passage 2 iA is provided which releases the packing 22 against the effect of high pressure steam which may leak past stem i1.

We claim:

In a iluid pressure control valve, comprising in combination, a valve casing having high pressure admission and iirst and second delivery ports, a valve stem of uniform diameter throughout slidable within the bore of said casing, `said stem having a hollow core forming `a central passage at its lower end with cross ports connecting therewith adapted to register with the high pressure admission port through said cross ports and said central passage when said stem is inone of two effective positions, and to close said high pressure port and establish communication between the iirst and second named` ports when in the other relative position, a stuffing box through which the stem enters'the casing, an exhaust vent passage connecting the lower end of the stuffing box with the second named delivery port, and

3 control means for operating said stemto either Number one or the other of its eiective positions. 444.263 JAMES L. KIMBALL. 1,280,010 ROY C. EAR/LEY. 1,588,972 5 1,747,899 REFERENCES CITED 1,764.79@ v The following references ate of record in the 1335289 me of this patent: ggi UNITED STATES PATENTS m 118741293 Number Name Date 1,982,071 120,033 Butler oct, 17. 1871 29131480 340,107 Fulton Apr. 20, 1886.

4 Name Date Acton Jan. 6. 1891 Garrison v Sept. 24, `1918 Machacek June 15. 1926 Hogg Feb. 18, 1930 Hook June 17. 1930 Tucker Dec. 16, 1930 Dunham Feb. l0, 1931 Helmstaedter July\7. 1981 Hook Aug. 30, 1932 Roberts Nov. 27, 1984 Sandvoss Sept. 3. 1935 

